Encrypt connector sensitive data

Add database field level encryption level to sensitive data to reduce
the risk in term of data leak. I dedice to have only one key for now in
a near future I may move to one master key and one encryption key per
organization to make rotation easiest.

I don't use built-in pg_crypto function to have clear seperation and
avoid any encryption key leak.

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/coredata/migrations/20250420T110200Z.sql

@@ -0,0 +1,4 @@
+DELETE FROM connectors;
+
+ALTER TABLE connectors DROP COLUMN connection;
+ALTER TABLE connectors ADD COLUMN encrypted_connection BYTEA NOT NULL;